genRCT: a statistical analysis framework for generalizing RCT findings to real-world population

When evaluating the real-world treatment effect, the analysis based on randomized clinical trials (RCTs) often introduces generalizability bias due to the difference in risk factors between the trial participants and the real-world patient population. This problem of lack of generalizability associated with the RCT-only analysis can be addressed by leveraging observational studies with large sample sizes that are representative of the real-world population. A set of novel statistical methods, termed "genRCT", for improving the generalizability of the trial has been developed using calibration weighting, which enforces the covariates balance between the RCT and observational study. This paper aims to review statistical methods for generalizing the RCT findings by harnessing information from large observational studies that represent real-world patients. Specifically, we discuss the choices of data sources and variables to meet key theoretical assumptions and principles. We introduce and compare estimation methods for continuous, binary, and survival endpoints. We showcase the use of the R package genRCT through a case study that estimates the average treatment effect of adjuvant chemotherapy for the stage 1B non-small cell lung patients represented by a large cancer registry.

Predictors of trimodality therapy in patients with muscle-invasive bladder cancer and effect on survival

BACKGROUND

Due to its unique advantages over radical cystectomy (RC), trimodality therapy (TMT) is increasingly being utilized by patients diagnosed with muscle-invasive bladder cancer (MIBC) who are not suitable for or refuse RC. However, achieving a satisfactory oncological outcome with TMT requires strict patient selection criteria, and the comparative oncological outcomes of TMT versus RC remain controversial.

METHODS

Patients diagnosed with non-metastatic MIBC who underwent TMT or RC were identified from the SEER database during 2004-2015. Before one-to-one propensity score matching (PSM), logistic regression was utilized to identify predictors of TMT. After matching, K-M curves were generated to estimate cancer-specific survival (CSS) and overall survival (OS) with log-rank to test the significance. Finally, we conducted univariate and multivariate Cox analyses to identify independent prognostic factors for CSS and OS.

RESULTS

The RC and TMT groups included 5812 and 1260 patients, respectively, and the TMT patients were significantly older than the RC patients. Patients with advanced age, separated, divorced, or widowed (SDW) or unmarried marital status (married as reference), and larger tumor size (< 40 mm as reference) were more likely to be treated with TMT. After PSM, TMT was found to be associated with worse CSS and OS, and it was identified as an independent risk factor for both CSS and OS.

CONCLUSION

MIBC patients may not be carefully evaluated prior to TMT, and some non-ideal candidates underwent TMT. TMT resulted in worse CSS and OS in the contemporary era, but these results may be biased. Strict TMT candidate criteria and TMT treatment modality should be required.

Improving trial generalizability using observational studies

Complementary features of randomized controlled trials (RCTs) and observational studies (OSs) can be used jointly to estimate the average treatment effect of a target population. We propose a calibration weighting estimator that enforces the covariate balance between the RCT and OS, therefore improving the trial-based estimator's generalizability. Exploiting semiparametric efficiency theory, we propose a doubly robust augmented calibration weighting estimator that achieves the efficiency bound derived under the identification assumptions. A nonparametric sieve method is provided as an alternative to the parametric approach, which enables the robust approximation of the nuisance functions and data-adaptive selection of outcome predictors for calibration. We establish asymptotic results and confirm the finite sample performances of the proposed estimators by simulation experiments and an application on the estimation of the treatment effect of adjuvant chemotherapy for early-stage non-small-cell lung patients after surgery.

Bias Reduction through Analysis of Competing Events (BRACE) Correction to Address Cancer Treatment Selection Bias in Observational Data

BACKGROUND

Cancer treatments can paradoxically appear to reduce the risk of non-cancer mortality in observational studies, due to residual confounding. Here we introduce a method, Bias Reduction through Analysis of Competing Events (BRACE), to reduce bias in the presence of residual confounding.

METHODS

BRACE is a novel method for adjusting for bias from residual confounding in proportional hazards models. Using standard simulation methods, we compared BRACE vs. Cox proportional hazards regression in the presence of an unmeasured confounder. We examined estimator distributions, bias, mean squared error (MSE), and coverage probability. We then estimated treatment effects of high vs. low intensity treatments in 36,630 prostate cancer, 4,069 lung cancer, and 7,117 head/neck cancer patients, using the Veterans Affairs database. We analyzed treatment effects on cancer-specific mortality (CSM), non-cancer mortality (NCM), and overall survival (OS), using conventional multivariable Cox and propensity score (adjusted using inverse probability weighting) models, vs. BRACE-adjusted estimates.

RESULTS

In simulations with residual confounding, BRACE uniformly reduced both bias and MSE. In the absence of bias, BRACE introduced bias toward the null, albeit with lower MSE. BRACE markedly improved coverage probability, but with a tendency toward overcorrection for effective but non-toxic treatments. For each clinical cohort, more intensive treatments were associated with significantly reduced hazards for CSM, NCM, and OS. BRACE attenuated OS estimates, yielding results more consistent with findings from randomized trials and meta-analyses.

CONCLUSIONS

BRACE reduces bias and MSE when residual confounding is present and represents a novel approach to improve treatment effect estimation in non-randomized studies.

Opportunities and Challenges of Observational Studies and Randomized Controlled Trials for Evaluating the Therapeutic Efficacy of COVID-19 Convalescent Plasma

Large randomized controlled trials (RCTs) remain the gold standard for evaluating treatment efficacy. However, observational studies, including non-randomized cohort studies, as well as small RCTs have gained increasing attention especially during the SARS-CoV-2 pandemic where critical evaluation of limited therapeutic options are sought to improve patient care while awaiting results for subsequent RCTs. As the authors have previously discussed, RCTs and observational studies are complementary approaches which often appear synergistic with one another. While not all real-world studies are the same, the results of observational studies are notoriously subject to both known and unknown confounding factors. The utilization of COVID-19 Convalescent Plasma is a timely illustration of evaluating the efficacy and safety of a COVID-19 therapy given the dangerous and often lethal effects of the virus and the limited approved therapeutic options for the disease. While awaiting the results of large RCTS of convalescent plasma, serval observational cohorts and small RCTs have attempted to assess the efficacy and safety of this approach with very mixed results. Among the likely reasons for this failure to provide a definitive answer concerning the value of convalescent plasma are the many limitations inherent to addressing treatment efficacy in non-randomized studies. While such studies are often able to capture information on large numbers of individuals rapidly, it is important to understand that although larger numbers may enhance the precision of estimates provided, larger numbers, in and of themselves, do not increase the accuracy of estimates due to patient selection and other biases. At the same time, both observational studies and small RCTS are at risk for publication bias due to investigator, reviewer and editorial bias toward positive studies. In this commentary we discuss the advantages and limitations of these methodologic approaches when addressing urgently needed evidence on the effectiveness and safety of therapies in a crisis such as the COVID-19 pandemic.

Efficacy of Neoadjuvant Chemotherapy with Epirubicin and Cyclophosphamide and Weekly Paclitaxel and Trastuzumab in Human Epidermal Growth Factor Receptor 2-Positive Breast Carcinoma: A Real-World Study

BACKGROUND

Trastuzumab has been introduced a decade ago and demonstrated improvement in the prognosis in patients with human epidermal growth factor receptor 2- (HER2-) positive (+) breast carcinoma (BC). This study is aimed at evaluating the efficacy of epirubicin/cyclophosphamide with weekly paclitaxel-trastuzumab as neoadjuvant chemotherapies in HER2+ BC patients.

METHODS

A total of 234 HER2+ BC patients were given neoadjuvant chemotherapy (NAC) between 2010 and 2016. The primary endpoints were pathologic complete response (pCR) and disease-free survival (DFS). Univariate and multivariate analyses of clinical and pathological factors associated with pCR and DFS were conducted.

RESULTS

The pCR (30.4% vs. 14.8%; P = 0.004) and DFS (P = 0.036) showed significant differences between patients administered with neoadjuvant trastuzumab therapy and those who did not. Multivariate logistic regression analysis showed that neoadjuvant trastuzumab treatment was regarded as an independent predictor of pCR. Patients with pCR had prolonged DFS (P = 0.025). In patients who did not achieve pCR (non-pCR), those who received trastuzumab had more prolonged DFS (P = 0.046). The luminal B/HER2+ subtypes had prolonged DFS when compared with nonluminal B/HER2+ subtypes (P = 0.010). The luminal B/HER2+ subgroup also showed improved DFS in non-pCR patients (P = 0.010). In the subgroup of non-pCR, the luminal B/HER2+ subgroup administered with trastuzumab showed no superior DFS (P = 0.168). However, a positive result was observed in patients without trastuzumab (P = 0.039). Multivariate analysis showed cT stage (P = 0.006) and tumor grade (P = 0.041), considering them as significant prognostic factors of DFS.

CONCLUSIONS

HER2+ BC patients showed improvement in pCR and DFS after neoadjuvant trastuzumab treatment. Patients without pCR had prolonged DFS after trastuzumab maintenance. Although the prognosis of luminal B/HER2+ BC showed favorable outcomes in the non-pCR subgroup, those receiving trastuzumab showed no survival advantage.

Untapped Potential of Observational Research to Inform Clinical Decision Making: American Society of Clinical Oncology Research Statement

ASCO believes that high-quality observational studies can advance evidence-based practice for cancer care and are complementary to randomized controlled trials (RCTs). Observational studies can generate hypotheses by evaluating novel exposures or biomarkers and by revealing patterns of care and relationships that might not otherwise be discovered. Researchers can then test these hypotheses in RCTs. Observational studies can also answer or inform questions that either have not been or cannot be answered by RCTs. In addition, observational studies can be used for postmarketing surveillance of new cancer treatments, particularly in vulnerable populations. The incorporation of observational research as part of clinical decision making is consistent with the position of many leading institutions. ASCO identified five overarching recommendations to enhance the role of observational research in clinical decision making: (1) improve the quality of electronic health data available for research, (2) improve interoperability and the exchange of electronic health information, (3) ensure the use of rigorous observational research methodologies, (4) promote transparent reporting of observational research studies, and (5) protect patient privacy.

Collaborative Review of Risk Benefit Trade-offs Between Partial and Radical Nephrectomy in the Management of Anatomically Complex Renal Masses

BACKGROUND

While partial nephrectomy (PN) is the recommended treatment for many small renal masses, anatomically complex tumors necessitate a clear understanding of the potential risks and benefits of PN and radical nephrectomy (RN).

OBJECTIVE

To critically review the comparative effectiveness evidence of PN versus RN; to describe key trade-offs involved in this treatment decision; and to highlight gaps in the current literature.

EVIDENCE ACQUISITION

A collaborative critical review of the medical literature was conducted.

EVIDENCE SYNTHESIS

Patients who undergo PN for an anatomically complex or large mass may be exposed to perioperative and potential oncologic risks that could be avoided if RN were performed, while patients who undergo RN may forgo long-term benefits of renal preservation. Decision-making regarding the optimal treatment with PN or RN among patients with anatomically complex or large renal mass is highly nuanced and must balance the risks and benefits of each approach. Currently, high-quality evidence on comparative effectiveness is sparse. Retrospective comparisons are plagued by selection biases, while the one existing prospective randomized trial, albeit imperfect, suggests that nephron-sparing surgery may not benefit all patients.

CONCLUSIONS

For anatomically complex tumors, PN preserves renal parenchyma but may expose patients to higher perioperative risks than RN. The risks and benefits of each surgical approach must be better objectified for identification of patients most suitable for complex PN. A prospective randomized trial is warranted and would help in directing patient counseling.

PATIENT SUMMARY

Treatment decisions for complex renal masses require shared decision-making regarding the risk trade-offs between partial and radical nephrectomy.

Prostate Cancer Registries: Current Status and Future Directions

CONTEXT

Disease-specific registries that enroll a considerable number of patients play a major role in prostate cancer (PCa) research.

OBJECTIVE

To evaluate available registries, describe their strengths and limitations, and discuss the potential future role of PCa registries in outcomes research.

EVIDENCE ACQUISITION

We performed a literature review of the Medline, Embase, and Web of Science databases. The search strategy included the terms prostate cancer, outcomes, statistical approaches, population-based cohorts, registries of outcomes, and epidemiological studies, alone or in combination. We limited our search to studies published between January 2005 and January 2015.

EVIDENCE SYNTHESIS

Several population-based and prospective disease-specific registries are currently available for prostate cancer. Studies performed using these data sources provide important information on incidence and mortality, disease characteristics at presentation, risk factors, trends in utilization of health care services, disparities in access to treatment, quality of care, long-term oncologic and health-related quality of life outcomes, and costs associated with management of the disease. Although data from these registries have some limitations, statistical methods are available that can address certain biases and increase the internal and external validity of such analyses. In the future, improvements in data quality, collection of tissue samples, and the availability of data feedback to health care providers will increase the relevance of studies built on population-based and disease-specific registries.

CONCLUSIONS

The strengths and limitations of PCa registries should be carefully considered when planning studies using these databases. Although randomized controlled trials still provide the highest level of evidence, large registries play an important and growing role in advancing PCa research and care.

PATIENT SUMMARY

Several population-based and prospective disease-specific registries for prostate cancer are currently available. Analyses of data from these registries yield information that is clinically relevant for the management of patients with prostate cancer.

Inferring the Effects of Cancer Treatment: Divergent Results From Early Breast Cancer Trialists' Collaborative Group Meta-Analyses of Randomized Trials and Observational Data From SEER Registries

PURPOSE

To compare the effect of breast cancer radiotherapy as estimated from observational data with findings from randomized trials.

MATERIALS AND METHODS

Rate ratios were obtained for selected end points among 13,932 women randomly assigned to receive radiotherapy or not in trials contributing to recent meta-analyses by the Early Breast Cancer Trialists' Collaborative Group. Estimates of the same quantities were derived for 393,840 women registered with breast cancer in the US SEER registries between 1973 and 2008.

RESULTS

In the randomized trials, radiotherapy after breast-conserving surgery reduced mortality from both breast cancer (rate ratio, 0.82; 95% CI, 0.75 to 0.90) and all causes (rate ratio, 0.92; 95% CI, 0.86 to 0.99). Reductions of similar magnitude were seen in the trials of radiotherapy after mastectomy in node-positive disease (rate ratios, breast cancer 0.84; 95% CI, 0.76 to 0.94; all causes, 0.89; 95% CI, 0.81 to 0.97). In the observational data, radiotherapy after breast-conserving surgery was associated with much larger mortality reductions (rate ratios, breast cancer, 0.64; 95% CI, 0.62 to 0.66; all causes, 0.63; 95% CI, 0.62 to 0.65), whereas radiotherapy after mastectomy in node-positive disease was associated with substantial increases in mortality (rate ratios, breast cancer, 1.34; 95% CI, 1.31 to 1.37; all causes, 1.23; 95% CI, 1.22 to 1.25). Detailed adjustment of the observational data for potential confounders did not reduce the divergence from the randomized data.

CONCLUSION

This study of mortality after radiotherapy for breast cancer found strikingly divergent results between the Early Breast Cancer Trialists' Collaborative Group meta-analyses of randomized data and the SEER observational data, even when efforts had been made to remove confounding and selection biases. Nonrandomized comparisons are liable to provide misleading estimates of treatment effects. Therefore, they need careful justification every time they are used.

Aiming for ideal care: a proposed framework for cancer quality improvement

The authors review the advances made in oncology over the past 50 years and describe methods for closing the gap in care quality.

Validation of clinical prognostic indices for diffuse large B-cell lymphoma in the National Cancer Data Base

BACKGROUND

Accurate risk stratification is necessary for epidemiologic and outcomes research in diffuse large B-cell lymphoma (DLBCL). We evaluated performance characteristics of the clinically derived International Prognostic Index (IPI) and revised IPI (R-IPI) with a regression model-based score using the National Cancer Data Base.

METHODS

We studied DLBCL patients diagnosed in 2004-2011, divided into derivation and validation cohorts. The model-based score was calculated from a Cox model incorporating variables routinely recorded by cancer registries. Calibration and discrimination of the indices with regard to overall survival were evaluated in the validation cohort.

RESULTS

The IPI was recorded in 19,511 of 119,942 patients, of whom 79 % received chemotherapy. Both clinical indices provided good survival discrimination (5-year estimate range 33-74 % for the IPI, and 41-87 % for the R-IPI), but explained only 16 % of variation in survival. Survival predictions among chemotherapy-treated patients were similar to estimates from published clinical cohorts. The model-based score had significantly better discrimination characteristics (5-year survival estimate range 22-87 %) and explained 23 % of variation in survival.

CONCLUSIONS

We validated the IPI and R-IPI as recorded by cancer registries to provide robust risk stratification in the general population with DLBCL, but a prognostic model using raw registry data provides superior performance. Explicit recording of prognostic factors is preferable to abstracting coarsened clinical indices for the purpose of population-based epidemiologic research. Considering low variation of survival explained by the standard clinical variables, incorporating molecular markers into registry data is necessary to improve risk stratification.

Complications after radical prostatectomy or radiotherapy for prostate cancer: results of a population-based, propensity score-matched analysis

OBJECTIVE

To assess rates of treatment-related complications after radical prostatectomy or radiotherapy monotherapy, using propensity score matching to account for baseline differences between these patient populations.

METHODS

On the basis of a population-based study of men undergoing surgery or radiotherapy for prostate cancer in Ontario between 2002 and 2009, we undertook a propensity score-matched analysis including age, comorbidity, and year of treatment to assess treatment-related complication end points. These included hospital admission; urologic, rectal, or anal procedures; open surgeries; and secondary malignancies.

RESULTS

From the original cohort of 32,465 patients, 15,870 (48.9%) had surgery and 16,595 (51.1%) had radiation. Propensity score matching produced 8797 pairs (17,594 patients). Among these, when compared with patients treated with surgery, those treated with radiation experienced fewer admissions to hospital (hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.78-0.92) and urologic procedures (HR, 0.50; 95% CI, 0.46-0.53) at year 1 but higher rates at year 3 (HR, 5.65; 95% CI, 4.61-6.91 and HR, 1.86; 95% CI, 1.62-2.13, respectively) and year 5. Although there was no significant difference in open surgeries at year 1, patients undergoing radiotherapy were at higher risk by year 3 (HR, 2.06; 95% CI, 1.23-3.47) and this rose by year 5. Over the study period, patients undergoing radiotherapy experienced more rectal-anal procedures (HR, 2.64; 95% CI, 2.37-2.95) and were diagnosed with more secondary malignancies (HR, 2.44; 95% CI, 1.16-5.14). Direct matching produced similar results.

CONCLUSION

From a propensity score-matched analysis, we found that patients undergoing radiation therapy for prostate cancer had higher rates of long-term complications in all 5 categories studied than patients undergoing surgery.

Considerations for observational research using large data sets in radiation oncology

The radiation oncology community has witnessed growing interest in observational research conducted using large-scale data sources such as registries and claims-based data sets. With the growing emphasis on observational analyses in health care, the radiation oncology community must possess a sophisticated understanding of the methodological considerations of such studies in order to evaluate evidence appropriately to guide practice and policy. Because observational research has unique features that distinguish it from clinical trials and other forms of traditional radiation oncology research, the International Journal of Radiation Oncology, Biology, Physics assembled a panel of experts in health services research to provide a concise and well-referenced review, intended to be informative for the lay reader, as well as for scholars who wish to embark on such research without prior experience. This review begins by discussing the types of research questions relevant to radiation oncology that large-scale databases may help illuminate. It then describes major potential data sources for such endeavors, including information regarding access and insights regarding the strengths and limitations of each. Finally, it provides guidance regarding the analytical challenges that observational studies must confront, along with discussion of the techniques that have been developed to help minimize the impact of certain common analytical issues in observational analysis. Features characterizing a well-designed observational study include clearly defined research questions, careful selection of an appropriate data source, consultation with investigators with relevant methodological expertise, inclusion of sensitivity analyses, caution not to overinterpret small but significant differences, and recognition of limitations when trying to evaluate causality. This review concludes that carefully designed and executed studies using observational data that possess these qualities hold substantial promise for advancing our understanding of many unanswered questions of importance to the field of radiation oncology.

Models of assessment of comparative outcomes of robot-assisted surgery: best evidence regarding the superiority or inferiority of robot-assisted radical prostatectomy

The widespread dissemination of robot-assisted radical prostatectomy (RARP) occurred despite the absence of high-level evidence supporting its safety and efficacy in patients with clinically localized prostate cancer. This study aims at systematically evaluating the models adopted in scientific reports assessing the comparative effectiveness of RARP versus open radical prostatectomy (ORP). Although several retrospective observational studies have assessed the comparative effectiveness of RARP and ORP, currently no published randomized data are available to comprehensively evaluate this issue. Furthermore, well-designed prospective investigations are needed to ultimately assess the benefits of RARP compared with other treatment modalities in patients with clinically localized prostate cancer.

Comparative effectiveness research: moving medical oncology forward

Comparative effectiveness research (CER) is critically needed in medical oncology to improve the care being delivered to oncology patients. As medical oncologists are forced to rely on insufficient data as a part of daily treatment decision making, and as the cancer treatment landscape evolves quickly relative to other areas of medicine, CER is particularly pressing in our field. Continued reliance on randomized clinical trials is a part of the solution, but it cannot be the sole answer. As new and richer data sources become available addressing quality of life, resource utilization, and other critical elements, the implementation of CER will advance. Its true power will lie in linkages to "learning health systems" and real-time application to the day-to-day practice of medicine.

Is radical nephrectomy a legitimate therapeutic option in patients with renal masses amenable to nephron-sparing surgery?

The decision to perform a radical nephrectomy (RN) or a partial nephrectomy (PN), not unlike most decisions in clinical practice, ultimately hinges on the balance of risk. Do the higher risks of a more complex surgery (PN) justify the theoretical benefits of kidney tissue preservation? Data suggest that for patients with an anatomically complex renal mass and a normal contralateral kidney, for whom additional surgical intensity may be risky, such as the elderly and comorbid, RN presents a robust treatment option. Nevertheless, PN, especially for small and anatomically simple renal masses in young patients without comorbidities should remain the surgical reference standard, as preservation of renal tissue can serve as an 'insurance policy' not only against future renal functional decline, but also against the possibility of tumour development in the contralateral kidney. In the present review, we outline the ongoing debate between the role of RN and PN in treatment of the enhancing renal mass.

Eribulin mesylate in pretreated breast cancer patients: a multicenter retrospective observational study

Background: Eribulin was recently approved in patients progressing after being treated with anthracyclines and taxanes and after two or more chemotherapy lines for advanced disease.

Objectives: This multicenter observational retrospective study was performed in order to evaluate activity and tolerability of eribulin in real-world patient population.

Methods: 133 advanced breast cancer patients pretreated with ≥ 2 chemotherapy lines for metastatic disease were retrospectively enrolled in the observational trial in 11 italian cancer centres.

Results: A median of 5 cycles of eribulin (range, 1-15) were administered. Twenty-eight partial responses were observed, for an overall response rate of 21.1% (95%CI,14.1-28.0). A stable disease was recorded in 57 patients (42.8%), and a clinical benefit (response or stable disease lasting ≥ six months) was observed in 51 patients (38.3%, 95%CI, 30.1-46.6). The subgroup analysis showed that a significant improvement in term of partial response and clinical benefit was achieved when eribulin was administered in HER-2 negative tumors (p=0.01 and p=0.004, respectively) and when it is given as third-line (p=0.09 and p=0.02, respectively). Toxicity was manageable; fatigue is the most common side effect observed, usually of low-grade, and clearly cumulative-dose related.

Conclusions: In this retrospective, observational analysis eribulin confirmed its efficacy and manageable tolerability even in real-world population and in heavily pretreated patients.

Comparative effectiveness research in oncology

Although randomized controlled trials represent the gold standard for comparative effective research (CER), a number of additional methods are available when randomized controlled trials are lacking or inconclusive because of the limitations of such trials. In addition to more relevant, efficient, and generalizable trials, there is a need for additional approaches utilizing rigorous methodology while fully recognizing their inherent limitations. CER is an important construct for defining and summarizing evidence on effectiveness and safety and comparing the value of competing strategies so that patients, providers, and policymakers can be offered appropriate recommendations for optimal patient care. Nevertheless, methodological as well as political and social challenges for CER remain. CER requires constant and sophisticated methodological oversight of study design and analysis similar to that required for randomized trials to reduce the potential for bias. At the same time, if appropriately conducted, CER offers an opportunity to identify the most effective and safe approach to patient care. Despite rising and unsustainable increases in health care costs, an even greater challenge to the implementation of CER arises from the social and political environment questioning the very motives and goals of CER. Oncologists and oncology professional societies are uniquely positioned to provide informed clinical and methodological expertise to steer the appropriate application of CER toward critical discussions related to health care costs, cost-effectiveness, and the comparative value of the available options for appropriate care of patients with cancer.

Effectiveness of neoadjuvant trastuzumab and chemotherapy in HER2-overexpressing breast cancer

Purpose

Trastuzumab and chemotherapy is the current standard of care in HER2+ early or locally advanced breast cancer, but there are scanty literature data of its real world effectiveness.

Methods

We retrospectively reviewed 205 patients with HER2+ breast cancer diagnosed in 10 Italian Medical Oncology Units between July 2003 and October 2011. All patients received neoadjuvant systemic therapy (NST) with trastuzumab in association with chemotherapy. Many different chemotherapy regimens were used, even if 90 % of patients received schemes including anthracyclines and 99 % received taxanes. NST was administered for more than 21 weeks (median: 24) in 130/205 (63.4 %) patients, while trastuzumab was given for more than 12 weeks (median: 12 weeks) in 101/205 (49.3 %) patients. pCR/0 was defined as ypT0+ypN0, and pCR/is as ypT0/is+ypN0.

Results

pCR/0 was obtained in 24.8 % and pCR/is in 46.8 % of the patients. At multivariate logistic regression, nonluminal/HER2+ tumors (P < 0.0001) and more than 12 weeks of neoadjuvant trastuzumab treatment (P = 0.03) were independent predictors of pCR/0. Median disease-free survival (DFS) and cancer-specific survival (CSS) have not been reached at the time of analysis. At multivariate analysis, nonluminal/HER2+ subclass (DFS: P = 0.01 and CSS: P = 0.01) and pathological stage II–III at surgery (DFS: P < 0.0001 and CSS: P = 0.001) were the only variables significantly associated with a worse long-term outcome.

Conclusions

Our data set the relevance of molecular subclasses and residual tumor burden after neoadjuvant as the most relevant prognostic factors for survival in this cohort of patients.

Management of localized kidney cancer: calculating cancer-specific mortality and competing risks of death for surgery and nonsurgical management

BACKGROUND

For elderly individuals with localized renal cell carcinoma (RCC), surgical intervention remains the primary treatment option but may not benefit patients with limited life expectancy.

OBJECTIVE

To calculate the trade-offs between surgical excision and nonsurgical management (NSM) with respect to competing causes of mortality.

DESIGN, SETTING, AND PARTICIPANTS

Relying on a cohort of Medicare beneficiaries, all patients with nonmetastatic node-negative T1 RCC between 1988 and 2005 were abstracted.

INTERVENTION

All patients were treated with partial nephrectomy (PN), radical nephrectomy (RN), or NSM.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cancer-specific mortality (CSM) and other-cause mortality (OCM) rates were modeled through competing-risks regression methodologies. Instrumental variable analysis was used to account for the potential biases associated with measured and unmeasured confounders.

RESULTS AND LIMITATIONS

A total of 10 595 patients were identified. In instrumental variable analysis, patients treated with PN (hazard ratio [HR]: 0.45; 95% confidence interval [CI], 0.24-0.83; p=0.01) or RN (HR: 0.58; 95% CI, 0.35-0.96; p=0.03) had a significantly lower risk of CSM than those treated with NSM. In subanalyses restricted to patients ≥ 75 yr, the instrumental variable analysis failed to detect any statistically significant difference between PN (HR: 0.48; p=0.1) or RN (HR: 0.57; p=0.1) relative to NSM with respect to CSM. Similar trends were observed in T1a RCC only.

CONCLUSIONS

PN or RN is associated with a reduction of CSM among older patients diagnosed with localized RCC, compared with NSM. The same benefit failed to reach statistical significance among patients ≥ 75 yr. The harms of surgery need to be weighed against the marginal survival benefit for some patients.